Trastuzumab is commonly used to treat women with breast cancers that produce large amounts of the HER2 protein. However, in some women, the breast cancer continues to grow despite trastuzumab therapy.
In this study, researchers are evaluating the safety and effectiveness of combining two drugs, neratinib and temsirolimus, in women with HER2-positive breast cancer that persists despite prior trastuzumab therapy. Women with triple-negative breast cancer will also be part of this study. These cancers do not express HER2 nor contain estrogen or progesterone receptors, and women with these cancers have limited treatment options.
Neratinib is an investigational drug that blocks some of the functions of the HER2 protein, and has been shown to be effective in HER2-positive cancers that have grown while on trastuzumab therapy. Temsirolimus is approved for the treatment of advanced kidney cancer, but its use in breast cancer is considered investigational. It works on another protein called mTOR that HER2 stimulates.